docstr: Tests, whether zero-hot is properly done when fill=0.
docstr_tok: ["Tests",",","whether","zero-hot","is","properly","done","when","fill=0","."]
code: def test_get_with_fill_0_and_zero_hot(self):
      """Tests, whether zero-hot is properly done when fill=0."""
      buffer = BufferWithInfiniteLookback(
          data=[0, 1, 0, 1],
          # Specify a space, so we can fill and one-hot discrete data properly.
          space=gym.spaces.Discrete(2),
      )
  
      # Test on ongoing and finalized buffer.
      for finalized in [False, True]:
          if finalized:
              buffer.finalize()
  
          self.assertTrue(len(buffer), 4)
  
          # Right side fill 0. Should be zero-hot.
          check(buffer.get(4, fill=0, one_hot_discrete=True), [0, 0])
          check(
              buffer.get(
                  -1,
                  neg_indices_left_of_zero=True,
                  fill=0,
                  one_hot_discrete=True,
              ),
              [0, 0],
          )
  
file_path: ray/rllib/env/tests/test_lookback_buffer.py
imports: import unittest
  import gymnasium
  import numpy
  from ray.rllib.env.utils import BufferWithInfiniteLookback
  from ray.rllib.utils.spaces.space_utils import batch, get_dummy_batch_for_space
  from ray.rllib.utils.test_utils import check
label_desc: Use image node_id 7 for calling the TestBufferWithInfiniteLookback obj's underlying member method code with example usage: obj.test_get_with_fill_0_and_zero_hot() without return types